Clinical, epidemiological and molecular features of the HIV-1 subtype C and recombinant forms that are circulating in the city of São Paulo, Brazil
- Equal contributors
1 Laboratory of Dermatology and Immunodeficiencies, Department of Dermatology, Medical School of São Paulo University, LIM56/FMUSP. Av. Dr. Eneas de Carvalho Aguiar, 470, IMT II, 3° andar, 05403-000, São Paulo, SP, Brazil
2 São Paulo Institute of Tropical Medicine–University of São Paulo, São Paulo, Brazil
3 Laboratory of Aids and Molecular Immunology, Oswaldo Cruz Institute–FioCruz, Rio de Janeiro, RJ, Brazil
Virology Journal 2012, 9:156 doi:10.1186/1743-422X-9-156Published: 9 August 2012
The city of Sao Paulo has the highest AIDS case rate, with nearly 60% in Brazil. Despite, several studies involving molecular epidemiology, lack of data regarding a large cohort study has not been published from this city.
This study aimed to describe the HIV-1 subtypes, recombinant forms and drug resistance mutations, according to subtype, with emphasis on subtype C and BC recombinants in the city of São Paulo, Brazil.
RNA was extracted from the plasma samples of 302 HIV-1-seropositive subjects, of which 211 were drug-naive and 82 were exposed to ART. HIV-1 partial pol region sequences were used in phylogenetic analyses for subtyping and identification of drug resistance mutations. The envelope gene of subtype C and BC samples was also sequenced.
From partial pol gene analyses, 239 samples (79.1%) were assigned as subtype B, 23 (7.6%) were F1, 16 (5.3%) were subtype C and 24 (8%) were mosaics (3 CRF28/CRF29-like). The subtype C and BC recombinants were mainly identified in drug-naïve patients (72.7%) and the heterosexual risk exposure category (86.3%), whereas for subtype B, these values were 69.9% and 57.3%, respectively (p = 0.97 and p = 0.015, respectively). An increasing trend of subtype C and BC recombinants was observed (p < 0.01).
The HIV-1 subtype C and CRFs seem to have emerged over the last few years in the city of São Paulo, principally among the heterosexual population. These findings may have an impact on preventive measures and vaccine development in Brazil.